Org Chem II Chpt 9 Aldehyde and Ketone

Which of the following starting materials and reaction conditions can be used to synthesize pentanal?

• 
• 
• 
• 

Which of the following is the product of nucleophilic addition of cyanide anion (NC^-) to benzaldehyde, followed by protonation?

• 
• 
• 
• 

In the formation of carbonyl hydrate from aldehydes or ketones, the water molecule can be described as

• a nucleophile

• an electrophile

• an oxidant

• a reductant

Which of the following statement about acetal or hemiacetal is correct?

• Acetal can only be formed under acidic conditions.

• Hemiacetal can be used as a protecting group to protect an aldehyde or ketone from reduction by LiAlH₄.

• Hemiacetal can only be formed under acidic conditions.

• Acetal can be used as a protecting group to protect the oxidation of an aldehyde under the reaction condition of CrO₃/H₂SO₄(aq).

Which of the following reaction steps can be used to carry out this transformation?

• MeMgBr

• (1) LiAlH₄

  (2) Dess-Martin periodinane

• (1) MeOH, H⁺

  (2) MeMgBr

  (3) H₂O, H₃O⁺

• (1) NaBH₄

  (2) MeI

Which of the following is the expected result from the reaction of glucose and NaBH₄?

• 
• 
• 
• no reaction

Draw the expected imine product obtained from cyclohexanone and CH₃CH₂CH₂NH₂.

Draw the expected acetal product obtained from 4-methylbenzaldehyde and ethanol.

Which of the following is/are possible conjugate addition product in the following cyclohex-2-en-1-one? (There may be more than one correct answer.)

• 
• 
• 
•